The present invention relates to a rotor and a motor.
As rotors for use in motors, permanent magnet field rotors of a Lundell-type structure have been known. For example, refer to Japanese Unexamined Utility Model Application Publication No. 5-43749. In the rotor, two rotor cores, each of which includes a plurality of claw-like magnetic poles arranged in a circumferential direction, are assembled to each other and one field magnet is arranged between these rotor cores. The claw-like magnetic poles in one of the rotor cores and the claw-like magnetic poles in the other rotor core are arranged alternately in the circumferential direction and function as magnetic poles with mutually different polarities.
In the rotor disclosed in the above publication, magnetic flux leakage is reduced in the rotor by firm attachment of back side auxiliary magnets onto radially inner surfaces of claw-like magnetic poles.
However, even though magnetic flux leakage is reduced by back side auxiliary magnets in the above rotor, further reduction of magnetic flux leakage is desired in commercialization in order to achieve higher efficiency and higher output.